Electric glow-lamp.



W. NERNST.

ELECTRIC GLOW LAMP.

APPLICATION FILED MAR. 29, 1898.

6201061 of'w WW6 non-602M w/unz colal.

' INVENTOR ATTO EV Patented Oct. 6, 1908.

UNITED STATES PATENT OFFICE.

WALTHER NERNST, OF GGTTINGEN, GERMANY, ASSIGNOR, BY MESNE ASSIGNMENTS, TO

NERNST LAMP COMPANY, OF PITTSBURG,

sYLvANIA.

PENNSYLVANIA, A CORPORATION OF PENN- ELEGTRIO GLOW-LAMP.

Specification of Letters Patent.

Patented Oct. 6, mos.

Application filed March 29, 1898. Serial No. 676,603.

To all 'whom it may concern:

Be it known that I, WALTHER NERNs'r', a subject of the German Emperor, residin at Gottingen, in the Kingdom of Prussia, erman Em ire, have invented certain new and useful mprovements in Electric ,Glow- Lamps, of whichthe following is a specification.

My invention relates to the class of electric lamps in which the light emitting element or member is a non-conductor at ordinary temperatures and which may be made. conduct- 1% by subjecting it to a relatively high degree of heat.

- The object of my invention is to provide a light emitting member or glower of such composition of materials as shall spiiicially adapt it for eflicient service and long I have found that a glower formed of a mixture of certain materials will become conductlve at a'lower temperature and be more durable in service than a glower made 'of a single material, provided the materials are thoroughly powdered and mixed together,

then combined with a suitable binding material, and formed into the proper shape and thoroughly baked, suitable terminals of con ducting material being attached to the ends of the glower in order to facilitate connecting it in circuit for operation.

My invention contemplates the employment of any one of a considerable variety of mixtures of materials, but mixtures of two or more of the oxids of zirconium, yttrium,

. erally be found most desirable.

thorium, beryllium, and magnesium will gen- I may however, combine one of these oxids, such, or example, as the oxid of ma nesium, with a' small percentage ofboric aci chlorid of calcium, tun stic' acid, or the like. en a glower formed of a proper mixture of two or more of the materials above specified is connected in an electric circuit and heated to its conducting temperature, the heat developed in itself by-the passage of a current therethrough will serve to maintain it in a conducting condition and cause it to yield light in a very efiicient manner.

As an illustration of my invention, I show, in the accompanying drawing-31a glower 1 which is a non-conductor at or ary temperatures. As a simple means for raising the glower to conducting temperature, I show a torch 2 su ported upon a suitable base 3.

It is to be understood that the illustration is in no sense restrictive, as regards either the form and dimensions of the glower or the means employed for heating it to conducting temperature.

I claim as my invention:

1. An im roved lower for electrical incandescent amps w 'ch is a non-conductor when cold but which becomes a good conductor and incandescent under the action of an electric current at hi h temperatures, and which consists essentially of a mixture of refractory metallic oxids/ 2. An improved glower forelectrical 1ncandescent lam s which is a non-conductor at normal atmosp eric temperatures but wh ch readily becomes conductive and incandescent. under the action of an electric current'when heated, comprising a mixture of zirconium readily becomes conductive and incandescent under the action of an electric current when heated, comprising a mixture of zircomum oxid with thorium oxid'. I

Signed at Berlin this 17 da of March 1898.

WALTH R NERNST. Witnesses: 1

Units. H. DAY, PAUL E. YHuo'rrNEa. 

